<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>注册页面</title>
    <style>

        .form-group{
            margin-bottom: 1.5rem;
        }
        label{
            display: block;
            margin-bottom: 0.5rem;
            font-weight: 500;
            color: #333;
        }
        #phone{
            width: 100%;
            padding: 0.8rem;
            border: 1px solid #ddd;
            border-radius: 4px;
            font-size: 1rem;
            box-sizing: border-box;
            transition: border-color 0.3s,dox-shadow 0.3x;
        }
        #phone:invalid{
            border-color: #ff444f;
            box-shadow:  0 0 2px rgba(255, 68, 68, 0.2);
        }
        #phone:focus{
            outline: none;
            border-color: hsl(356, 100%, 63%);
            box-shadow: 0 0 2px rgba(red, green, blue, alpha);
        }
        button:hover{
           background-color: #1976D2;
        }
        button{
            width: 100%;
            padding: 0.8rem;
            border:none;
            border-radius: 4px;
            background-color: #2196F3;
            color:white;
            font-size: 1rem;
            cursor: pointer;
            transition: round-color 0.3s;
        }
        .form-container{
            max-width: 400px;
            padding: 2rem;
            border: 1px solid #eee;
            border-radius: 8px;
            box-shadow:  0 0 10px rgba(0, 0, 0, 0.05);
        }
        .page-container{
            height: 300px;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        .form-container{
            flex-grow: 1;
        }

    </style>
</head>
<body>
    <div class="page-container">
        <div class="form-container">
            <form action=""method="get">
                <div class="form-group">
                    <label for="phone">手机号</label>
                    <input name="phone"
                    type="tel"
                    id="phone"
                    pattern="^1[3-9]\d{9}$"
                    autocomplete="off"autofocus
                    title="请输入正确手机号"
                    placeholder="请输入手机号">
                </div>
             <button >注册</button>
        </div>
    </div>
</form>
</body>
</html>